Optical disks are used to store data and are normally designed for use with a specific type of disk drive with which the disks are compatible. When a user inserts an optical disk into a disk drive with which the optical disk is compatible, the optical disk reads electronically coded data on the optical disk to obtain instructions and information regarding writing data to and/or reading data from the optical disk.
However, when a user inserts an optical disk into a disk drive with which the optical disk is incompatible, there can be problems. The disk drive may not be able to track the incompatible optical disk or may employ a different wavelength laser than is necessary to read the electronically coded data stored on the optical disk. Another reason a disk drive may not be able to track the incompatible disk is that the disk drive may be configured to read one generation of optical disk and the inserted optical disk is of another product generation, but is of the same form factor, or size. In situations such as these, the disk drive may not receive the necessary instructions from the optical disk to read data from or write data to the optical disk.
Additionally, information regarding the optical disk may need to be read from the optical disk at different locations along optical disk manufacturing and distribution channels. This information may include logistic or security information relating to the optical disk. If the information is stored on the optical disk as electrically coded data, the optical disk must be inserted into a compatible disk drive and spun to read this information. In this case, compatible disk drives must be provided at the various locations along the distribution and manufacturing channels where the information is to be read from the optical disk. The provision of such disk drives may be expensive. Moreover, having to insert each optical disk into a disk drive to obtain this basic information therefrom may be cumbersome, and time consuming.
The following U.S. patents disclose information relating to the disposition of markings on optical disks: U.S. Pat. No. 4,961,077, U.S. Pat. No. 5,541,904, and U.S. Pat. No. 6,052,465, all of which are hereby incorporated by reference in their respective entireties.